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Flowering intensity in white yam (Dioscorea rotundata)

Published online by Cambridge University Press:  02 April 2009

E. I. HAMADINA
Affiliation:
International Institute of Tropical Agriculture, Oyo Road, Ibadan, Nigeria
P. Q. CRAUFURD*
Affiliation:
Plant Environment Laboratory, University of Reading, Cutbush Lane, ReadingRG2 9AF, UK
R. ASIEDU
Affiliation:
International Institute of Tropical Agriculture, Oyo Road, Ibadan, Nigeria
*
*To whom all correspondence should be addressed. Email: [email protected]

Summary

White or Guinea yam (Dioscorea rotundata), grown for its underground tubers, is an important food in West Africa. Progress in yam breeding is constrained by variable flowering behaviour, making hybridization difficult. Yam clones may be dioecious, monoecious or hermaphrodite with variable sex ratios. The proportion of plants that flower and the flowering intensity also vary with season and location. The objective of the present work was to investigate whether variation in flowering behaviour was related to factors determining rate of development (photoperiod and temperature through sowing date, location and year) or growth (cumulative solar radiation and temperature). Sex ratios, the proportion of plants that had flower buds and open flowers, and the number of flowers or spikes was recorded in one male (TDr 131) and one female (TDr 99-9) clone of white yam grown in the field in Nigeria at three locations and at different sowing dates. Clone TDr 131 was uniformly male flowering, while clone TDr 99-9 exhibited a number of sex types with gynoecious, monoecious and trimonoecious plants observed. The proportion of flowering plants was low in both clones, averaging 0·34 in clone TDr 131 and 0·13 in clone TDr 99-9. Day of vine emergence had a significant and contrasting effect on the proportion of flowering plants and on flowering intensity in the two clones. In clone TDr 131, the proportion of flowering plants and flowering intensity declined with later vine emergence at all locations (r=0·43–0·53; P<0·05), whereas in clone TDr 99-9 the proportion of flowering plants increased with later emergence (r=0·46, P<0·01). In clone TDr 131, this response was strongly associated with warmer temperatures (r=0·49–0·50; P<0·05) and greater cumulative radiation (r=0·85–0·93; P<0·001) between vine emergence and flowering, rather than photoperiod at vine emergence. This suggests that flowering behaviour in the male clone TDr 131 is strongly influenced by factors that affect growth rather than development. Clone TDr 99-9, on the other hand, exhibited no clear relations between flowering and growth or developmental factors, though the proportion of flowering plants and flowering intensity was greatest at planting dates close to the longest day and at temperatures of 25–26°C. This might suggest that flowering behaviour in clone TDr 99-9 is controlled by photothermal responses.

Type
Crops and Soils
Copyright
Copyright © Cambridge University Press 2009

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References

REFERENCES

Abraham, K. (1997). Flowering deficiencies and sterility preventing natural seed set in Dioscorea alata cultivars. Tropical Agriculture 74, 272276.Google Scholar
Abraham, K. & Nair, S. G. (1979). Anomalies in sex expression of Dioscorea rotundata Poir. Journal of Root Crops 5, 1924.Google Scholar
Akoroda, M. O. (1984). Patterns of set multiplication ratio among seed-derived biparental females of white yam (D. rotundata Poir.). Zeitschrift fur Planzenzuchtung 93, 280290.Google Scholar
Akoroda, M. O. (1985). Sexual seed production in white yam. Seed Science and Technology 13, 571581.Google Scholar
Akoroda, M. O., Wilson, J. E. & Chheda, H. R. (1984). The association of sexuality with plant traits and tuber yield in white yam. Euphytica 33, 435442.CrossRefGoogle Scholar
Asiedu, R., Ng, S. Y. C., Bai, K. V., Ekanayake, I. J. & Wanyera, N. M. W. (1998). Genetic Improvement. In Food Yams: Advances in Research (Eds Orkwor, G. C., Asiedu, R. & Ekanayake, I. J.), pp. 63–104. Ibadan, Nigeria: NRCRI and IITA.Google Scholar
Bai, K. V. & Ekanayake, I. J. (1998). Taxonomy, morphology and floral biology. In Food Yams: Advances in Research (Eds Orkwor, G. C., Asiedu, R. & Ekanayake, I. J.), pp. 1338. Ibadan, Nigeria: NRCRI and IITA.Google Scholar
Burkill, H. M. (1960). Organography and evolution of Dioscoreacea, the family of yams. Journal of the Linnean Society (Botany) 56, 319412.CrossRefGoogle Scholar
Coursey, D. G. (1967). Yams. An Account of the Nature, Origins, Cultivation and Utilisation of the Useful Members of the Dioscoreaceae. Tropical Agricultural Series. London, UK: Longmans, Green and Co. Ltd.Google Scholar
Craufurd, P. Q., Summerfield, R. J., Asiedu, R. & Vara Prasad, P. V. (2001). Dormancy in yams (Dioscorea spp.). Experimental Agriculture 37, 147181.CrossRefGoogle Scholar
Degras, L. (1993). The Yam: A Tropical Root Crop. Harlow: MacMillan.Google Scholar
Doku, E. V. (1985). Sex expression and tuber yields of seedlings and clones derived from seedling tubers of white yam (Dioscorea rotundata). Legon Agricultural Research Bulletin 1, 1317.Google Scholar
Edem, E. U. (1975). Preliminary investigation into the effect of planting dates and types of setts on flowering of white yam varieties. Federal Department of Agricultural Research, Ibadan, Nigeria Memo 115, pp. 6. Ibadan: FGN.Google Scholar
Flohr, M. L., Williams, J. H. & Lenz, F. (1990). The effect of photoperiod on the reproductive development of a photoperiod sensitive groundnut (Arachis hypogaea L.) cv. NC AC 17090. Experimental Agriculture 26, 397406.CrossRefGoogle Scholar
Hariprakash, C. S. & Nambisan, B. (1996). Carbohydrate metabolism during dormancy and sprouting in yam (Dioscorea) tubers: changes in carbohydrate constituents in yam (Dioscorea) tubers during dormancy and sprouting. Journal of Agricultural and Food Chemistry 44, 30663069.CrossRefGoogle Scholar
Ile, E. I., Craufurd, P. Q., Asiedu, R. & Battey, N. H. (2007). Duration from vine emergence to flowering suggests a long-day or rate of change of photoperiod response in white yam (Dioscorea rotundata Poir.). Environmental and Experimental Botany 60, 8694.CrossRefGoogle Scholar
McDonald, J. H. (2008). Handbook of Biological Statistics. Baltimore, MD: Sparky House Publishing.Google Scholar
Okereke, O. U. (1978). Prospects of yam seed industry in Nigeria. In Proceedings of the First National Seminar on Root and Tuber Crops (Eds Ene, L. S. O., Okereke, H. E., Odurukwe, S. O., Okoli, O. O. & Arene, O. B.), pp. 195197. Umudike, Nigeria: NRCR.Google Scholar
Roberts, E. H. & Summerfield, R. J. (1987). Measurement and prediction of flowering in annual crops. In Manipulation of Flowering (Ed. Atherton, J. G.), pp. 1750. London: Butterworths.CrossRefGoogle Scholar
Sadik, S. & Okereke, O. U. (1975). Flowering, pollen grain germination, fruiting, seed germination and seedling development of white yam Dioscorea rotundata Poir. Annals of Botany 39, 597607.CrossRefGoogle Scholar
Scott, G. J., Best, R., Rosegrant, M. & Bokanga, M. (2000). Roots and Tubers in the Global Food System: A Vision Statement to the Year 2020. Lima, Peru: CIP.Google Scholar
Segnou, , Fatokun, C. A., Akoroda, M. O. & Hahn, S. K. (1992). Studies on the reproductive biology of white yam (Dioscorea rotundata Poir.). Euphytica 64, 197203.CrossRefGoogle Scholar
Swannell, M. C., Wheeler, T. R., Asiedu, R. & Craufurd, P. Q. (2003). Effect of harvest date on the dormancy period of yam (Dioscorea rotundata). Tropical Science 43, 103107.CrossRefGoogle Scholar
Yoshida, Y. & Kanahama, K. (1999). Effects of photoperiod and temperature on the development of spikes and new tubers in Chinese yam (Dioscorea opposita Tunb. Cv. Ichoimo). Journal of the Japanese Society of Horticultural Science 68, 124129.CrossRefGoogle Scholar
Zoundjihekpon, J. & Dansi, A. (1998). Biologie de la reproduction des ignames africaines. In L'igname, Plant Seculaire et Culture d'Avenir (Eds Berthaud, J., Bricas, N. & Marchand, J-L.), pp. 231240. Montpellier: CIRAD-INRA-CORAF.Google Scholar